Pin and clevis connection



A. R. MAIER PIN AND CLEVIS CONNECTION Dec. 21, 1943.

2 Sheets-"Sheet 1' Filed Aug. 23, 1939 A. R. MAIER PIN AND CLEVIS CONNECTION Dec. 21, 1943.

Filed Aug. 23, 1939 2 Sheets-Sheet 2 fnveizior: E Wan 5e Patented Dec. 21, 1943 PIN AND CLEVIS CONNECTION August R. Maier, Dallas, Tex., assignor to Oil Well Supply Company, a corporation of New Jersey Application August 23, 1939, Serial No. 291,586

1 Claim.

The present invention relates to central pumping powers, and more specifically to means for connecting the rotating member of a pumping power to a pull rod leading to a pumping unit such as used in pumping oil wells and the like.

One object of the invention is to provide improved means for connecting a pull rod clevis with the rotating member of a pumping power. A further object is to incorporate a roller bearing in the connection between the pull rod clevis and the rotating member of the pumping power. Another object is to provide an improved mechanical arrangement whereby the clevis bearing p n and the roller bearings thereof can be eiiectively lubricated. A further object is to construct and arrange the parts hereinafter disclosed in detail so that these singly and jointly perform the functions set forth in detail.

The above and further objects of the invention will be fully apparent from the following detail disclosure, when read in connection with the accompanying drawings.

In the drawings.

Figure 1 is a plan View showing a pumping power with a plurality of pull rods connected to the rotating member thereof, said rods being equipped with clevises and pin-connected roller bearings embodying the present invention:

Figure 2 is an end elevation of Figure *1;

Figure 3 is an enlarged vertical section on the. line III-III of Figure 1;

Figure 4 is a horizontal section on line IVIV of Figure 3; and

Figure 5 is, a detail of the clevis pin.

Referring in detail to the drawings, the numeral 6 represents the housing of a conventional form of pumping power which is adapted to be driven from a suitable prime mover through a shaft 1 and through beveled gears 8 and 8. On the same stub shaft with the beveled gear 8 there is a spur pinion it which drives the gear ll mounted on the vertical shaft ii of the central pumping power. This. shaft carries acrank' or eccentric it which in turn has secured thereto a crankpin M efiective to impart a rotating motion to the multiple. drive disk l5. This disk. has a plurality of holes 56- therei-n, any one of which is adapted to be connected with a clevis, ind cated generally at H, which clevis is connected to a pull rod it. As shown on the drawings, there are three such clevises and pull rods, each of which maybe assumed to be connected at a remote point with an oil well pumping jack. The pull reds are suitably guided in conventional knockofi posts l9,

The present invention relates specifically to improved means for effecting the connection between the pull rods E8 through especially designed clevises and anti-friction bearing pins operatively connected with the member l5. To

these ends, I provide an especially designed clevis pin bearing assembly so arranged that needle type roller bearings can be incorporated in such, manner that efiective lubrication is assured. The arrangement is such that a compact unit of long life is provided so as to secure eflicient transmission of power from the eccentric or crank disk. There-is a particular problem in clevis pin connections in the environment disclosed for the particular reason that the angle of motion between the pull rod and the rotating member i5- is relatively small, being of the order of from 3 to 5 degrees. It is important that the path-of each roller is sufiicient to overlap that of the roller next to it toprevent wearing a groove in either the roller race or the clevis pin in order that minimum wear and long life with efficient transmission of power can be secured. An ordinary sleeve type of bushing is unsatisfactory because the load is always in one direction and the lubrication is difficult to maintain. With such a small arc of movement excessive bearing pressures are set up and concentrated in a minimum area, which brings about excessive wear in a short time on bushing and pin. This excessive wear causes the pin to stick, and will result in bending and fatigue of pullrod connections, thus causing expensive repairs and unnecessary loss of production. The present invention overcomes this problem or difliculty by the provision of the detailed construction now to be described.

The details of the connection of the roller bearing pin connection between the clevis and the rotatingmember it are best shown in Figures 3 and 4.

Referring in detail to these figures, each clevis ll includes arms 22 and 24 and a clevis pin indicated generally at 26. At the top, this pin has a cylindrical flange 23, a portion of which is flattened off at St for engagement with a lug 32 upstanding from the upper arm 22 of the. clevis, which lug prevents relative rotation between the pin and the clevis. Below the flange thereis a cylindrical portion 3i which fits within an aperture in the clevis. The shoul-;

der below this cylindrical portion is provided with one or more grease-receiving notches 36; and complementary notches 3'! are formed in theiclevis arm 22 for supplying lubrication to the contactface of 22 on 15.

Below the cylindrical portion 34, there isa.

cylindrical portion 38 of slightly smaller diameter than the portion El i. Below portion. 38 there- 7 ing element 54.

there is a lower cylindrical shank 4s. The seat portion42 of the pin between flanges '38 and 46 coacts with small needle bearing rollers 50, which in turn are. surrounded with a bearing sleeve 52 mounted in one of the holes l6 above referred to.

packing, this element being of known construc:

tion obtainable in the .open market and whi ch'is normally located inside of bearing sleeve 52.

' The pin is drilled axially toprovide, a duct,

Below the flange 46 there is provided a; grease retainer or seal member 54 which com prises an annular'shell containing a resilient 1 have been specifically described as involving the as indicated at 56, and a suitable fitting 58 is screwed into the end of such duct so as to permit connection with a knowntype of grease gun. i Extending radially outward from the central-grease duct there area plurality of grease.

ports 60 which communicate with an annular space formed by' a peripheralgroove 62 in the a pin. Thus, grease forced under pressure through the duct 56 will be extruded through the ports 62 and will enter the interstices between the several bearing rollers 50. Such grease willwork its way upwardly through the notches 36 and 31 and'thus effectively lubricate the bearing sur-' face between the underside of the arm 22 of the clevis arm and the upper bearing face of therotating member l5. The grease will also work its way between the bearing rollers and thus lubricat'e'the inner peripheral roller bearing face of the sleeve 18. Such grease will also work its way downwardly over the upper face of I the retainer flange 46. The outflow of grease below the-bearing will bepreventedby the'pack- The'parts are so proportioned thattthelength of the sleeve 52 as measured axially thereof is greater than the dimension'between the top and bottom face of the disk l5. Thus,the top of the sleeve will extend a short'distance above the top face of, the disk 15. The purpose-of this isto prevent accumulatedwater from creeping'into the bearings Devices of this character used in the oil fields are exposed to the elements at all times'and it isimportant to prevent rain water from washing away thelubricant. By having the sleeve'projectabove the top face of the disk, water'is excluded from the bearing. The sleeve 52- makes a pressed fit with the hole. l6 and the lower extremity of the sleeve is substantially flush with the lower face of the disk I5. Preferably, a clearance indicated at 64 is provided be-' tween the under surface of the disk l5 and the, a upper surface of the clevis arm 24.- The shank 48 at the end of the pin 26 extends through the clevis arm 24 and a suitable cotter'pin or other lockingmeans 66 normally prevents withdrawal of the'clevis pin. 1

The device is constructed and arranged to permit ready removal'of'the pin and rollers as a unit. This is accomplished ,by removing the cotter pin 66 and forcing the pin upwardly' This will cause the .annular retainer flange 46 Y to force all of the rollers upwardly through the sleeve 52. During'such removal, inasmuch as the rollers are not provided witha cage, means are required to hold them in contact with the pin. In practice, this is accomplished by s napping arubber band or anytie'member around them, whereupon the rollers and the pin can be withdrawn from the assemblyf or replacement a pin, or various other expedients could be used by those skilled in the art to prevent the pin from turning in relation to the clevis.

' The connection between the pull rod and the clevis is especially adapted to resist the bending of the rod at the point adjacent the threaded portion thereof. To these ends, the clevis has an elongated hub 68 which is slit longitudinally at 10 and provided with a relatively long smooth longitudinal bore 12, the inner extremity of which is provided with screw threads 14 for engagement with corresponding threads formed on the extremity of the pull rod IS. The extreme end only of the pull rod is threaded into the threaded portion of the bore in originally assembling the parts, whereupon the slit hub is tightened by drawing up the nuts on the ends of the bolts i6 which pierce ears l8-formed on the hub. When the parts of the hub are thus firmly clamped to the pull rod, it will be apparent that the'same will be entirely relieved of bending strains immediately adjacent the point where the threads merge into the cylindrical part of the rod. This will prevent early failure, which has occurred in practice where the end of a rod is merely screwed on the end of a clevis hub. In such old construction, bending strains frequently resulted in fatiguing the rod at the zone 'Where thethreads merge into the adjacent part of the rod. This difficulty is overcome by the improved construction described.

While I have described quite specifically the embodiment of the invention herein illustrated, it is to be understood that various modifications and substitutions of equivalents may be made without departure fromthe invention, as defined by the appended claim.

I claim: 1

A vertical pin and horizontal clevis connection for connecting a pull rod to the rotating drive disk of a well pumping power, comprising a clevis having the under surface of its uppermost arm adapted to contact with and be supported by the upper surface of the disk, a vertical pin extending through the clevis and disk and having an enlarged annular portion in the said clevis arm, said annular pin portion and the under surface of the upper clevis arm having communicating outwardly extending lubricant passages, and bearing means including a sleeve in the disk surrounding the pin, said sleeve extending upwardly beyond the plane of the contacting surfaces of the disk and clevis arm in lubricant communi-- cation with said passages, permitting an upward and outward flow of lubricant from between the pin and sleeve to the said contacting surfaces of the clevis and disk but preventing a reverse flow of liquid to the pin in the plane of said surfaces, and means for introducing lubricant between said pin and sleeve.

AUGUST R. MAIER. 

